Preheat oven to 350°F
In a small frying quickly crumble and cook the sausage over medium heat
Remove the cooked sausage to a bowl
Using scissors chop the bacon into the hot frying pan and cook quickly
Meanwhile, grease the muffin tin cavities and chop the vegetables, if needed
In a large bowl, whisk together eggs and milk
Divide this egg mixture evenly into 4 small bowls
To the first bowl, add red bell pepper, yellow onion, and spinach
To the second bowl, add the cooked sausage
To the third bowl, add half the bacon and green bell pepper
To the fourth bowl, add the remaining bacon and diced tomato
Divide shredded cheese evenly across all four bowls and stir each to combine
Pour each mixture evenly into 3 muffin tin cups (totaling 12)
Bake for 12–14 minutes, or until eggs are set and cooked through
Let cool slightly before serving, or cool completely before freezing